Testing of Level Shifters in Multiple Voltage Designs

The use of multiple voltages for different cores is becoming a widely accepted technique for efficient power management. Level shifters are used as interfaces between voltage domains. Through extensive transistor level simulations of resistive open, bridging and resistive short faults, we have classified the testing of level shifters into PASSIVE and ACTIVE modes. We examine if high test coverage can be achieved in the PASSIVE mode. We consider resistive opens and shorts and show that, for testing purposes, consideration of purely digital fault effects is sufficient. Thus conventional digital DfT can be employed to test level shifters. In all cases, we conclude that using sets of single supply voltages for testing is sufficient

High Spatial Resolution Investigations of Microchannel Plate Imaging Properties for UV Detectors

Microchannel plate (MCP) photon counting detectors are currently being used with great success on many of the recent NASA/ESA ultraviolet (UV) astrophysics missions that make observations in the 1OO A - 1600 A range. These include HUT, the Wide Field Camera on ROSAT, EUVE, ALEXIS, ORFEUS, and SOHO. These devices have also been chosen to fly on future UV astrophysics missions such as FUSE, FUVITA, IMAGE, and both the HST STIS and Advanced Camera instruments. During the period of this award we have fabricated a dual-chamber vacuum test facility to carry out laboratory testing of detector resolution, image stability and linearity, and flat field performance to enable us to characterize the performance of MCPs and their associated read-out architectures. We have also fabricated and tested a laboratory 'test-bed' delay line detector, which can accommodate MCP's with a wide range of formats and run at high data rates, to continue our studies of MCP image fixed pattern noise, and particularly for new small pore MCP's which have recently come onto the market. These tests were mainly focussed on the assessment of cross delay-line (XDL) and double delay line (DDL) anode read-out schemes, with particular attention being focussed on flat-field and spatial resolution performance

Precision cosmology from future lensed gravitational wave and electromagnetic signals

The standard siren approach of gravitational wave cosmology appeals to the direct luminosity distance estimation through the waveform signals from inspiralling double compact binaries, especially those with electromagnetic counterparts providing redshifts. It is limited by the calibration uncertainties in strain amplitude and relies on the fine details of the waveform. The Einstein Telescope is expected to produce $10^4-10^5$ gravitational wave detections per year, $50-100$ of which will be lensed. Here we report a waveform-independent strategy to achieve precise cosmography by combining the accurately measured time delays from strongly lensed gravitational wave signals with the images and redshifts observed in the electromagnetic domain. We demonstrate that just 10 such systems can provide a Hubble constant uncertainty of $0.68\%$ for a flat Lambda Cold Dark Matter universe in the era of third generation ground-based detectors

AMiBA Wideband Analog Correlator

A wideband analog correlator has been constructed for the Yuan-Tseh Lee Array for Microwave Background Anisotropy. Lag correlators using analog multipliers provide large bandwidth and moderate frequency resolution. Broadband IF distribution, backend signal processing and control are described. Operating conditions for optimum sensitivity and linearity are discussed. From observations, a large effective bandwidth of around 10 GHz has been shown to provide sufficient sensitivity for detecting cosmic microwave background variations.Comment: 28 pages, 23 figures, ApJ in press

Relativistic Gravity and Binary Radio Pulsars

Following a summary of the basic principles of pulsar timing, we present a review of recent results from timing observations of relativistic binary pulsars. In particular, we summarize the status of timing observations of the much celebrated original binary pulsar PSR B1913+16, draw attention to the recent confirmation of strong evidence for geodetic precession in this system, review the recent measurement of multiple post-Keplerian binary parameters for PSR B1534+12, and describe the Parkes Multibeam survey, a major survey of the Galactic Plane which promises to discover new relativistic binary pulsar systems.Comment: 12 pages, 3 EPS figures, proceedings of 8th Canadian Conference on General Relativity and Relativistic Astrophysics, held June 1999, McGill University, Montreal, Quebec, Canad

Effects of selctive lesions of the nucleus basalis magnocellularis on working memory in rats.

The nucleus basalis magnocellularis (NBM) of the rat brain is analogous to the nucleus basalis of Meynert found in humans. Alzheimer's disease patients have working memory impairments, which may be attributable to damage to the basal nucleus of Meynert. Excitotoxins such as quisqualic and ibotenic acid have been previously used to make lesions of the NBM in research animals. NBM lesions made with ibotenic or quisqualic acid are known to impair working memory. However, in addition to damaging the cholinergic neurons of the NBM, the lesions made by these excitotoxins also destroy cells of other nearby structures, and it is unclear whether the impairments found are due to damage to the NBM or to surrounding non-cholinergic structures. With the recent advent ofthe highly selective immunotoxin 192 IgG-saporin, it may be possible to determine if lesions involving only the cortically projecting NBM cholinergic neurons impair working memory. The current experiment tests the hypothesis that selective lesions of cholinergic neurons of the NBM impair working memory. To test this hypothesis, a delayed non-matching-to-position-task was used as a test for working memory. Results of this experiment provide novel evidence of the involvement of the cholinergic neurons of the NBM in working memory and will contribute to our understanding of the cognitive impairments seen in Alzheimer's disease.Michelle Marie NobleButt, Allen.EDuong,TaihungHermann,DouglasSheets, VirgilMaster of ArtsDepartment of PsychologyCunningham Memorial library, Terre Haute,Indiana State UniversityILL-ETD-039MastersTitle from document title page. Document formatted into pages: contains 46 p.: ill. Includes abstract and appendix

Testing Gravity with Pulsars in the SKA Era

The Square Kilometre Array (SKA) will use pulsars to enable precise measurements of strong gravity effects in pulsar systems, which yield tests of gravitational theories that cannot be carried out anywhere else. The Galactic census of pulsars will discover dozens of relativistic pulsar systems, possibly including pulsar -- black hole binaries which can be used to test the "cosmic censorship conjecture" and the "no-hair theorem". Also, the SKA's remarkable sensitivity will vastly improve the timing precision of millisecond pulsars, allowing probes of potential deviations from general relativity (GR). Aspects of gravitation to be explored include tests of strong equivalence principles, gravitational dipole radiation, extra field components of gravitation, gravitomagnetism, and spacetime symmetries.Comment: 20 pages, 4 figures, to be published in: "Advancing Astrophysics with the Square Kilometre Array", Proceedings of Science, PoS(AASKA14)04